1. Field of the Invention
The subject invention relates generally to the field of reclaiming or recycling waste materials and, more particularly, to the reclaiming of fiber reinforcement from fiber reinforced plastic waste materials.
2. Description of the Prior Art
Historically, virtually all sheet molding composite (SMC) scrap generated by SMC molders has been sent to landfills for disposal. As the costs associated with landfilling increase however, it has become more economically feasible to consider alternative solutions for dealing with such wastes. Current methodology for reclaiming cured SMC waste involves a staged process of shredding, particalizing and either ultra fine grinding or through reduction by pyrolysis. Neither of these methods is entirely satisfactory from an economic standpoint in that the recyclable material produced is usable generally only as filler material in recycled plastic products. Since a substantial portion of the cured SMC waste is composed of glass fiber reinforcement having a substantially higher cost than filler material, there is a strong economic reasons to separate the fiber reinforcement from the binder material for reuse. While methods such as high speed impacting, hammermilling and grinding have been proposed to reclaim the fiber reinforcement, none of these methods is particularly satisfactory because the energy, maintenance and depreciation costs of these methods is very expensive and the reclaimed fibers are broken and have lost much of their original strength characteristics.
My invention solves the problem of how to efficiently separate fiber reinforcment from fiber reinforced plastic waste materials for reuse by using a roller mill system to accomplish the separation step. Roller mill systems generally have been known for many years. Over the past several generations roller mill technology has been applied to many commercial applications involving for example the size reduction of materials such as cereal grains and friable minerals. However, the use of roller mill technology in connection with the processing of fiber reinforced Plastic materials to effect separation of the fiber reinforcement represents a new application for this technology not heretofore suggested by its previous uses.